Telecommunication service providers are able to provide data services across their networks. In order to increase the area over which data may be transmitted, service providers can contract data transport services from other service providers.
For example, a service provider who wishes to provide global IP virtual private network (VPN) services might contract transport services from access providers to reach enterprise sites that are not directly connected to the service provider's domain.
Traditionally, service providers use a manual process to negotiate and contract transport services. However, with an increased need for fast service delivery, service providers have an incentive to establish a cross-provider service management layer that allows them to interact and buy each other's services through an automated process.
For example, through such an automated process, one service provider could offer transit service, e.g., transport for data traffic, and another service provider can purchase the offered transit service. However, there is uncertainty as to what information a service provider needs to advertise to enable another service provider to create end-to-end connectivity across multiple domains without sacrificing the service provider's security.
Traditionally, the general solution is to use a routing protocol such as Border Gateway Protocol (BGP) to advertise connectivity. However, BGP does not allow service providers to take into account commercial, regulatory and other constraints that determine which end-to-end connectivity options are acceptable and/or optimal. For other transport protocols, such as Ethernet, alternative solutions would be required.
To address these issues adjacencies and Inter-carrier Interfaces were defined in “Adjacencies (previously known as Association Points.” IPsphere Forum, RAWG Contribution, September 2007. An adjacency is the existence of connectivity between two resource domains. An adjacency includes one or more Inter-carrier Interfaces (ICIs) between the two resource domains. An ICI is a physical interface between two service providers. More specifically, an ICI is a direct physical interface between two network elements that are owned and operated by two different service providers.
An adjacency specifies the existence of ICIs without specifying every ICI. This allows neighboring service providers to advertise connectivity between their networks without allowing other service providers to know how many physical interfaces (and the exact nature of those interfaces) exist between the neighboring service providers.
A resource domain is the collection of network elements, cables, etc. that is under control of a service provider. More specifically, a resource domain is a collection of network equipment owned by an Element Owner (EO). A resource domain is similar to an Autonomous System that is used in Internet-related standards, but an Autonomous System usually only refers to IP and MPLS equipment.
An EO is a service provider that offers services, such as data transport services or content distribution to other service providers. Examples of elements include a transport network, access to residential subscribers in an area, content servers, caching devices, billing systems and authentication systems.
An administrative owner (AO) is a service provider who does end-to-end service composition. An AO is a role that any participating service provider can take. For example, when a service provider wants to offer a service to the service provider's residential or enterprise customers for whom the service provider needs to subcontract service from other service providers, the service provider becomes the AO which buys elements from the EOs. Thus, the AO is able to offer service to end customers.
EOs advertise service through element templates, which is a standardized data structure. With respect to data transport services, an element template specifies adjacencies and the protocols carried over those adjacencies. By comparing element templates, an Administrative owner (AO) can select which templates work best to provide an end-to-end transmission.
FIG. 1 illustrates a system including multiple resource domains and EOs. A system 100 may include resource domains 110, 120 and 130. The system 100 may be the Internet, for example.
As shown, each of the resource domains 110, 120 and 130 are coupled to each other. Each of the resource domains 110, 120 and 130 includes elements (not shown) which are owned by EOs 115, 125 and 135, respectively. As described above, each of the EOs 115, 125 and 135 is also a service provider that owns the resource domains 110, 120 and 130, respectively.
Each of the EOs 115, 125 and 135 publish an element template regarding the adjacencies and protocols carried over those adjacencies for each the EOs 115, 125 and 135 respective elements. An AO 150 receives the published element templates. The AO 150 may be any one of the service providers that owns the resource domains 110, 120 and 130. Based on the element templates, the AO 150 decides a path 170 for end-to-end connectivity.
FIG. 2 illustrates a Multiprotocol Label Switching (MPLS)/Ethernet interface between two resource domains.
As shown in FIG. 2, an MPLS/Ethernet interface 200 exists between a first resource domain 220 and a second resource domain 260. The first resource domain 220 includes an MPLS switch 240 and the second resource domain 260 includes an MPLS switch 280. The Ethernet layer is terminated in the MPLS switches 240 and 280. Therefore, the MPLS/Ethernet interface 200 cannot be used to carry end-to-end Ethernet traffic, since the MPLS switches 240 and 280 do not switch Ethernet packets.
FIG. 3 illustrates another MPLS/Ethernet interface between two resource domains. As shown in FIG. 3, an MPLS/Ethernet interface 300 exists between a first resource domain 320 and a second resource domain 360. The first resource domain 320 includes an Ethernet switch 325 connected to MPLS switches 330 and 335. Similarly, the second resource domain 360 includes an Ethernet switch 365 connected to MPLS switches 370 and 375. As shown, Ethernet traffic will be switched through the Ethernet switches 325 and 365, but will be terminated in the MPLS switches 330, 335, 370 and 375. Therefore, the MPLS/Ethernet interface 300 cannot be used to carry end-to-end Ethernet traffic.
Consequently, publishing adjacency information that identifies the transmission protocol on the inter-carrier interface is not sufficient to successfully advertise what kind of data transport service can be supported through a resource domain.